Considering how well ketchup sells, I had to throw the down vote here, even though the post is otherwise excellent.
And I'm definitely with you on the exact recipe being the real key. Your typical generic is going to be over sweet and over vinegared because sugar and vinegar are usually cheaper than tomatoes.
Good ketchup, and I agree that Heinz is kinda the standard for a big brand, is not often found in big brands. Great ketchup is almost always going to be small batch because you can only standardize tomatoes so much. You have to tweak the sugar, vinegar, and spices to balance things. Anything much over a hundred gallons and you're fucked because there's just no way to be both great and standardized.
The only exception to that in the condiment world I know of is French's yellow mustard. They have somehow managed to make their mustard consistent between batches, over decades, and it is the best yellow mustard across the board. They do sacrifice some depth of flavor in doing so, but you can't make a yellow mustard that matches the flavor in small batches. I'm not saying everyone will like it, but ifyou like yellow mustard, you aren't going to find better.